diff --git a/experimental/babel-preset-env/package.json b/experimental/babel-preset-env/package.json
index 7b7a30724f..4cca9aaa4e 100644
--- a/experimental/babel-preset-env/package.json
+++ b/experimental/babel-preset-env/package.json
@@ -55,9 +55,8 @@
     "babel-preset-es2015": "^6.14.0",
     "babel-register": "^6.14.0",
     "compat-table": "kangax/compat-table#b0cec63ea21f3a7788a8eececcb918de903b7fc5",
-    "eslint": "^3.3.1",
-    "eslint-config-babel": "^3.0.0",
-    "eslint-plugin-babel": "^4.0.0",
+    "eslint": "^3.13.1",
+    "eslint-config-babel": "^5.0.0",
     "eslint-plugin-flowtype": "^2.29.1",
     "lodash": "^4.15.0",
     "mocha": "^3.0.2",
diff --git a/experimental/babel-preset-env/scripts/build-data.js b/experimental/babel-preset-env/scripts/build-data.js
index 79f1f20532..ee1a504810 100644
--- a/experimental/babel-preset-env/scripts/build-data.js
+++ b/experimental/babel-preset-env/scripts/build-data.js
@@ -80,7 +80,7 @@ const envMap = {
 };
 
 const getLowestImplementedVersion = ({ features }, env) => {
-  let tests = flatten(compatibilityTests
+  const tests = flatten(compatibilityTests
     .filter((test) => {
       return features.indexOf(test.name) >= 0 ||
       // for features === ["DataView"]
@@ -104,7 +104,7 @@ const getLowestImplementedVersion = ({ features }, env) => {
     })
   );
 
-  let envTests = tests
+  const envTests = tests
     .map(({ res: test, name, isBuiltIn }, i) => {
       // Babel itself doesn't implement the feature correctly,
       // don't count against it
@@ -133,7 +133,7 @@ const getLowestImplementedVersion = ({ features }, env) => {
       .shift();
     });
 
-  let envFiltered = envTests.filter((t) => t);
+  const envFiltered = envTests.filter((t) => t);
   if (envTests.length > envFiltered.length || envTests.length === 0) {
     // envTests.forEach((test, i) => {
     //   if (!test) {
diff --git a/experimental/babel-preset-env/src/index.js b/experimental/babel-preset-env/src/index.js
index 27bb413426..85ef642efa 100644
--- a/experimental/babel-preset-env/src/index.js
+++ b/experimental/babel-preset-env/src/index.js
@@ -111,7 +111,7 @@ export const electronVersionToChromeVersion = (semverVer) => {
     throw new Error("Electron version must be a semver version");
   }
 
-  let result = electronToChromium[m[1]];
+  const result = electronToChromium[m[1]];
   if (!result) {
     throw new Error(`Electron version ${m[1]} is either too old or too new`);
   }
@@ -122,7 +122,7 @@ export const electronVersionToChromeVersion = (semverVer) => {
 const _extends = Object.assign || function (target) {
   for (let i = 1; i < arguments.length; i++) {
     const source = arguments[i];
-    for (let key in source) {
+    for (const key in source) {
       if (Object.prototype.hasOwnProperty.call(source, key)) {
         target[key] = source[key];
       }
@@ -178,7 +178,7 @@ export function validatePluginsOption(opts = [], type) {
     throw new Error(`The '${type}' option must be an Array<string> of plugins/built-ins`);
   }
 
-  let unknownOpts = [];
+  const unknownOpts = [];
   opts.forEach((opt) => {
     if (validIncludesAndExcludes.indexOf(opt) === -1) {
       unknownOpts.push(opt);
@@ -201,7 +201,7 @@ const validateIncludeOption = (opts) => validatePluginsOption(opts, "include");
 const validateExcludeOption = (opts) => validatePluginsOption(opts, "exclude");
 
 export function checkDuplicateIncludeExcludes(include, exclude) {
-  let duplicates = [];
+  const duplicates = [];
   include.forEach((opt) => {
     if (exclude.indexOf(opt) >= 0) {
       duplicates.push(opt);
@@ -254,7 +254,7 @@ export default function buildPreset(context, opts = {}) {
   const useBuiltIns = opts.useBuiltIns;
 
   const filterPlugins = filterItem.bind(null, targets, exclude.plugins, pluginList);
-  let transformations = Object.keys(pluginList)
+  const transformations = Object.keys(pluginList)
     .filter(filterPlugins)
     .concat(include.plugins);
 
diff --git a/experimental/babel-preset-env/src/transform-polyfill-require-plugin.js b/experimental/babel-preset-env/src/transform-polyfill-require-plugin.js
index f0da6205f0..8ddbea3e1a 100644
--- a/experimental/babel-preset-env/src/transform-polyfill-require-plugin.js
+++ b/experimental/babel-preset-env/src/transform-polyfill-require-plugin.js
@@ -4,7 +4,7 @@ function isPolyfillSource(value) {
 
 export default function ({ types: t }) {
   function createImportDeclaration(polyfill) {
-    let declar = t.importDeclaration([], t.stringLiteral(polyfill));
+    const declar = t.importDeclaration([], t.stringLiteral(polyfill));
     declar._blockHoist = 3;
     return declar;
   }
@@ -43,7 +43,7 @@ export default function ({ types: t }) {
   }
 
   function createImports(polyfills, requireType, regenerator) {
-    let imports = polyfills
+    const imports = polyfills
     .filter((el, i, arr) => arr.indexOf(el) === i)
     .map((polyfill) => createImport(polyfill, requireType, true));
 
diff --git a/experimental/babel-preset-env/test/index.js b/experimental/babel-preset-env/test/index.js
index b43db5c5c7..3fc6753009 100644
--- a/experimental/babel-preset-env/test/index.js
+++ b/experimental/babel-preset-env/test/index.js
@@ -145,12 +145,11 @@ describe("babel-preset-env", () => {
     });
 
     it("doesn't throw when specifiying a decimal for node", () => {
-      let targets;
       const plugin = {
         node: 6
       };
 
-      targets = {
+      const targets = {
         "node": 6.5
       };